View Full Version : R400 reshuffling due to Xbox 2 contract?
It occured to me a couple of days ago that one of the main reasons why R400 was delayed and then subsequently canned might have had something to do with the Xbox 2 contract. I can't believe they found the technology totally unworkable for this product generation.
Say they put it off... the tech carried forward into R500 and based on preliminary R500 drafts a proposal was made to M$. Then they pushed forward with the co-development of desktop and console solutions (this would tally with bringing in the Marlborough team) while a powerful, current gen part (Loki) was drafted as a stop-gap.
Supporting this idea is the fact that the R&D run for Xbox 2 will be relatively short, so if ATi had something partway through development already then that would have worked in their favour. Everything regarding R400 has been kept extremely hush-hush, again perhaps suggesting a possible involvement with the contract. Also... remember all the R400 talk around the time of the R300 launch? It almost seemed as if they were more excited about it than the product being released at the time! Seems strange that they would apparently disregard such tremendous potential, unless of course it has been promoted to serve this "higher purpose".
Just idle speculation, but I haven't seen anybody mention this before.
MuFu.
Edit - sp.
Dave Baumann
19-Jun-2003, 01:28
"It occured to me" :?: :wink:
You know I am capable of *some* completely independent thought, Dave. :lol:
MuFu.
I thought the pullback was because there is no need for PS/VS 3.0 yet.
Heck I am still waiting for PS2.0 to show up in games.
As for Xbox 2, are you sure ATI has won that deal? You'd think the stock would be moving up.
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K.I.L.E.R
19-Jun-2003, 05:18
I thought the pullback was because there is no need for PS/VS 3.0 yet.
Heck I am still waiting for PS2.0 to show up in games.
As for Xbox 2, are you sure ATI has won that deal? You'd think the stock would be moving up.
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Ati's stock is like glue. It sticks to a value and then starts to wear out over the years. :lol:
I think we'll see PS/VS 3.0 in Loki/R420.
MuFu.
RussSchultz
19-Jun-2003, 12:54
Has it officially become Loki and not Loci?
If it´s supposed to be in reference to the norse god, then it´s Loki with a K
(Loke in Scandinavia).
Has it officially become Loki and not Loci?
Yes.
MuFu.
Another option is maybe the performance of the original R400 was meeting the design goals. Other than this I think the Microsoft idea is the most likely reason. I don't believe it's because a more flexible architecture isn't needed yet. That just sounds like marketing BS.
Dave Baumann
19-Jun-2003, 17:00
The real point here is one factor: the introduction of DX10.
Without DX10's availability until 2004/5 this leaves an element of flexibility in terms of specifications. It's quite possible that it just isn't worth a significantly new architecture later this year (at least, not in the same order of magnitude of R200 to R300) without a major API overhaul. The fact that DX9 looks to stay for at least another year may enable ATI to view this as a potential window of opportunity.
NV3x's issues are not just quoted as being down to the 130nm process but also a diversion of resources from the desktop development to the Xbox project - ATI's engineering must already be under some strain with desktop, chipset, set-top, mobile, palm parts as well as a new Nintendo development (in fact we know they are taking extreme measures already with the "physical" reuse). If you were to add an Xbox deal on top of that its would be hard not to see some impact on other projects.
Its likely that ATI know this all to well, but are aiming to minimise the impact on key deliverables, the biggest one being DX10 and Longhorn in the PC space - whatever happens between now and those is really just an interim measure and not a significant milestone (plus, R3x0 already has a lot of sway with OEM's so any competitors chips are going to have to be very good to convince those OEM's that have gone back to ATI to switch again). Given this, is a major architectural overhaul really that necessary? Probably not.
Its quite possible that ATI have already shuffled their development plans such they take that engineering hit now, during the interim period, as opposed to later when key deliverables are required. Rather than having a totally new architecture now, produce an evolved R300 based architecture (possibly adding PS/VS3.0 support) and then move you new architecture back, bumping features to DX10 and performance, and introduce a desktop variant and an Xbox variant as well.
Doomtrooper
19-Jun-2003, 17:09
ATI does have alot more reources in terms of people to work multiple projects though, but Sony has got both ATI and Nvidia leary of the challenges of the PS 3 chip.
There was also a Spong update:
http://spong.com/index.asp?art=5098
Evildeus
19-Jun-2003, 19:28
Well, it seems that 2006 according to the CEO of M$ (http://www.theinquirer.net/?article=10080), is the time set for the XBOX2 Launch. If that so, what are the consequencies on Ati? More diffuse scheddule between each new generation?
R300King!
20-Jun-2003, 00:41
Has it officially become Loki and not Loci?
Yes.
MuFu.
I thought it was Loki and not Loci. You had everyone fooled. haha
See here http://www.rage3d.com/board/showthread.php?s=463b136c0b429cace435139cc5c9172e&threadid=33684400&perpage=20&highlight=*Loki*&pagenumber=6#post1331942868
:lol:
antlers
20-Jun-2003, 00:54
It seems like it will be much more difficult for the XBox 2 to be backwards compatible if they switch GPU vendors. The XBox API isn't regular DirectX--I think it touches the hardware more directly. NVidia also supplies the sound chip and bridge. I don't know what kind of sound IP ATI has. If the XBox 2 isn't backwards compatible Microsoft is making a huge mistake. Maybe the XBox 2 will have both ATI and NVidia chips?
I think they canceled the R400 because the R300 was so damn good and could be made even better with process improvements--the R400 wouldn't have been a performance jump and the features weren't needed yet.
I think they canceled the R400 because the R300 was so damn good and could be made even better with process improvements--the R400 wouldn't have been a performance jump and the features weren't needed yet.
Well I still think that, along with what Dave says above is the most likely contributing factor.
No idea about the audio part but it's M$ - I suspect they'll figure something out, even if it means pissing people off. :)
MuFu.
Dave Baumann
20-Jun-2003, 01:12
In NV's conference call tonight it was said the XB2 would be backwards compatible regardless of whether NV was used or not.
High 5-HIAA
20-Jun-2003, 05:48
In NV's conference call tonight it was said the XB2 would be backwards compatible regardless of whether NV was used or not.
Wow! That certainly makes things more interesting.
I am also interested in what would take the place of the APU for sound chores in the XBox Next. It seems to me like MS would wish to keep the Dolby Digital ENcoding functions, which would be required for full backwards compatibility purposes. It's possible this could be done by the CPU of the XBoxNxt, but I would suspect not.
Perhaps an ATI Graphics core integrated into an Nvidia "chipset"? ;)
Dave Baumann
20-Jun-2003, 08:52
I doubt the implementation of Dolby encode would be particularily difficult since I would suspect that this is an "off the shelf" design offered by Dolby to anyone who is willing to stump up for a license.
In NV's conference call tonight it was said the XB2 would be backwards compatible regardless of whether NV was used or not.
Great catch Dave. Does ease the mind a little. Though it does make you wonder if they will be able to pull it off. I'm not so concerned about the non-graphics compatibility. I guess we'll find out when we find out. ;)
Tommy McClain
Dave Baumann
20-Jun-2003, 20:57
Great catch Dave. Does ease the mind a little. Though it does make you wonder if they will be able to pull it off. I'm not so concerned about the non-graphics compatibility. I guess we'll find out when we find out. ;)
Curiously enough, I appear to have been wrong about the DD enacode though - that was one of the few bits that was cited as being NV IP. I'd be surpiseed if there wasn't something that could be pruchased by Dolby though, and NVIDIA also said that it could probably be achieved through MS routines anyway.
All in all, there doesn't appear to be many compatibility concerns and certainly not from the graphics side. I had always thought that MS wouldn't be dumb enough to engineer themselves down a the route of a single supplier all the time as it leads them to getting stuffed even more on price than they feel they are at the moment!
All in all, there doesn't appear to be many compatibility concerns and certainly not from the graphics side. I had always thought that MS wouldn't be dumb enough to engineer themselves down a the route of a single supplier all the time as it leads them to getting stuffed even more on price than they feel they are at the moment!
Excellent point. I hope you're right. Bakward compatibility is definitely going to make or break the Xbox 2.
Tommy McClain
RussSchultz
20-Jun-2003, 22:21
Great catch Dave. Does ease the mind a little. Though it does make you wonder if they will be able to pull it off. I'm not so concerned about the non-graphics compatibility. I guess we'll find out when we find out. ;)
Curiously enough, I appear to have been wrong about the DD enacode though - that was one of the few bits that was cited as being NV IP. I'd be surpiseed if there wasn't something that could be pruchased by Dolby though, and NVIDIA also said that it could probably be achieved through MS routines anyway.
Their MCU (sound processor), and dolby digital encoding, was based on the Parthus Mozart Core, so presumably others could have licensed it also. Of course, Parthus has end of lifed the IP and no longer sells it so NVIDIA may have purchased the complete rights to it (assuming nobody else previously licensed Mozart)
It occured to me a couple of days ago that one of the main reasons why R400 was delayed and then subsequently canned might have had something to do with the Xbox 2 contract. I can't believe they found the technology totally unworkable for this product generation.
Say they put it off... the tech carried forward into R500 and based on preliminary R500 drafts a proposal was made to M$. Then they pushed forward with the co-development of desktop and console solutions (this would tally with bringing in the Marlborough team) while a powerful, current gen part (Loki) was drafted as a stop-gap.
Supporting this idea is the fact that the R&D run for Xbox 2 will be relatively short, so if ATi had something partway through development already then that would have worked in their favour. Everything regarding R400 has been kept extremely hush-hush, again perhaps suggesting a possible involvement with the contract. Also... remember all the R400 talk around the time of the R300 launch? It almost seemed as if they were more excited about it than the product being released at the time! Seems strange that they would apparently disregard such tremendous potential, unless of course it has been promoted to serve this "higher purpose".
Just idle speculation, but I haven't seen anybody mention this before.
MuFu.
Edit - sp.
If the quote about 2006 for the next xBox is accurate, that's an ocean of time in the biz and I just can't see any direct linkage to R400. If the R420 rumors are correct (nomenclature) that simply says to me that they've opted to improve their original R400 plans, but that R4xx is at least on track for a product announcement this year--if not a ship date this year.
I think M$ is feeling the heat for xBox losses and has been transferring that pressure to nVidia in terms of pricing, which M$ wants to force downward. As a result I think nVidia is tiring of the M$ xBox deal and sees it as a drain on its resources--reading between the lines of the latest nVidia conference call I didn't get the sense that nVidia was exuberant about continuing the xBox relationship.
I also got the feeling that M$ would like to advance the hardware base for xBox more rapidly--some mention of "floating"--that nVidia isn't particularly thrilled about. To be honest I'm not sure what was meant by "floating" and am just making some guesses about that. The fact that they've already been through arbitration indicates the relationship has soured. I think we might make a much better guess as to ATi's intentions and/or xBox probabilities if we knew a lot more about the nature of the problems currently afflicting the xBox nVidia-M$ relationship. Is it just over costs--or is their a technological aspect involved?
In NV's conference call tonight it was said the XB2 would be backwards compatible regardless of whether NV was used or not.
Yes, this would make a lot of sense considering how close to a PC the basic xBox software paradigm is. This could be a real advantage for M$ over the other console makers as the company could actually do annual hardware upgrades to the basic platform "silently" so to speak as the technology and pricing allows while still retaining full backwards compatability with the software base. xBox could theoretically benefit from the same product cycling and economies of scale the PC market enjoys. At ~$300 a year people could afford to purchase new boxes annually if they desired.
I wonder, though, about games already written for current xBox hardware which I would have thought would have to have been highly optimized for the current xBox hardware in order to perform well. Hmmm...just don't know that much about it.
If ATI were to gain the contract, they have the benefit of not being the first to attempt a PC in a box console. I pretty much think they would shove in their latest P4 chipset, and next Radeon. Not do what NV did and develop the lot from effectivly nothing (on their $400M advance payment I might add).
Do the decent thing...
Shove in their integrated RS400 (next gen), add an external sound chip... done. Keep the money. :D
Haven't you people see the heiniken Beer adverts? :D :twisted:
Looks like the 2006 date was incorrect--it's actually 2005, now.
http://news.com.com/2100-1043_3-1019181.html?tag=fd_top
It's funny, but I swear I saw this somewhere (TR?) and they'd originally put 2005 as the date but when I looked back it had been changed to 2006...thought the old peepers were acting out again...;) Guess not.
Anyway, it's certainly not inconceivable that a propspective xBox contract for 2005 production might have ATi shuffling around at present...However, the '05 date is one bandied about by analysts and not M$, so who knows...
nonamer
22-Jun-2003, 04:17
ATI does have alot more reources in terms of people to work multiple projects though, but Sony has got both ATI and Nvidia leary of the challenges of the PS 3 chip.
That's crazy IMO. NVidia has much more development resources than ATI, and they're not tied to developing a GPU for Nintendo, which I believe ATI is still committed to. Also, I think both ATI and NVidia are weary of the financial drain that developing for the XB2 would be, not the actually challenging of the PS3.
Yes, this would make a lot of sense considering how close to a PC the basic xBox software paradigm is. This could be a real advantage for M$ over the other console makers as the company could actually do annual hardware upgrades to the basic platform "silently" so to speak as the technology and pricing allows while still retaining full backwards compatability with the software base. xBox could theoretically benefit from the same product cycling and economies of scale the PC market enjoys. At ~$300 a year people could afford to purchase new boxes annually if they desired.
Consoles tend to be sold at a loss, and make money on the games. Therefore it doesn't make sense to provide incentives for people to upgrade every year.
I wonder, though, about games already written for current xBox hardware which I would have thought would have to have been highly optimized for the current xBox hardware in order to perform well. Hmmm...just don't know that much about it.
The hardware will be several times more powerful. I see no reason why old games will run any worse, even if they're not optimised for the new architecture.
Will be nice to run current titles at 1080p with 6xFSAA and 16xAF. :)
MuFu.
Consoles tend to be sold at a loss, and make money on the games. Therefore it doesn't make sense to provide incentives for people to upgrade every year.
That's M$'s central problem right now with xBox--they're losing money on them. And M$ pushing hard for lower prices from nVidia to stem the red ink is what's behind the problems between the companies, according to reports I've read. It's at least part of the problem. An intelligent console maker will want to break even on his hardware if he can.
The central idea behind a console is price. If you could keep the prices in line and at least break even at the ~$300 mark (costs between $250 and $275 per unit) and manage to upgrade the hardware 3-5x more often than your competition, you could make a huge drive into the market and greatly expand your software revenues. What I'm saying is that by virtue of what xBox is it need not be bounded by the same kind of hardware restraints that afflict PS2. xBox need not be afflicted by the need to "start over" every 5 years, etc.
The hardware will be several times more powerful. I see no reason why old games will run any worse, even if they're not optimised for the new architecture.
Good point, but I was referring to more definitive hardware optimization that might involve code which directly interfaces the hardware to wring the most performance out of it. Don't really know how much if any of that goes in xBox software, however...
cellarboy
23-Jun-2003, 05:35
Curiously enough, I appear to have been wrong about the DD enacode though - that was one of the few bits that was cited as being NV IP. I'd be surpiseed if there wasn't something that could be pruchased by Dolby though, and NVIDIA also said that it could probably be achieved through MS routines anyway.
Dolby do licence an "interactive encoding for entertainment" system.
http://www.dolby.com/ht/co_br_0110_IntroductionToInteractive.html
Cmedia have a software version of the system available for their CMI9739 AC'97 CODEC, so in a worst case situation, ATI could use a software solution to the DD5.1 encode problem/
In NV's conference call tonight it was said the XB2 would be backwards compatible regardless of whether NV was used or not.
Doesn't surprise me too much either.
M$ may be big and fat and greedy and mean, but they're not so stupid as to make themselves totally dependent to a single chip designer/IHV.
One other thing though:
I hope the Xbox2 project doesn't screw up Ati's product cycles the same way it did with nVidias.
I know there where other reasons, but it was a big factor, wasn't it?
Do I worry too much? :roll:
Cheers,
Mac
I hope the Xbox2 project doesn't screw up Ati's product cycles the same way it did with nVidias.
While I do not doubt that the XBox contract took a lot of engineers off other products I think people use that to more of an escape goat. Most of nV product cycles troubles is not based off a lack of engineers but rather by risky call(s) by management. Sometimes those calls work..some times they don't...
I see the R400 as being in the right place for inclusion in the next Xbox. I may be wrong on this, but doesn't a console need to be finished hardware wise around 6 month to a year before release? For the developers?
I may be wrong on this, but doesn't a console need to be finished hardware wise around 6 month to a year before release? For the developers?
Yes and no. No because early developers work off a dev kit that runs on a PC and merely simulates the characteristics of the final console design. This is periodically updated as the design gets more and more finalized.
Yes because the design needs to be finished easily 6 months prior to release just to work out manufacturing kinks and get the thing made and stockpiled in large enough quantities. Unlike GPUs, it is not acceptable for consoles to have a floating pseudo-release date and for hardware to slowly trickle into stores in the weeks and months following! And even GPUs have to have their design finalized several months before release to allow for testing and manufacturing.
Nearly everything in the hardware business takes longer than it seems on the outside.
nooneyouknow
30-Jun-2003, 14:27
ATI does have alot more reources in terms of people to work multiple projects though, but Sony has got both ATI and Nvidia leary of the challenges of the PS 3 chip.
That's crazy IMO. NVidia has much more development resources than ATI, and they're not tied to developing a GPU for Nintendo, which I believe ATI is still committed to. Also, I think both ATI and NVidia are weary of the financial drain that developing for the XB2 would be, not the actually challenging of the PS3.
Nonamer, actually, Doom is right. ATI has a huge # of development teams spread out across North America. Remember that they have at least 2 teams for PC development alone. Look at the breathe of their product lineup, it gives you an indication of just how many teams at their disposal. They are staffing up like mad now so I think that is an indication that they plan on putting as many teams together as needed with no impact to their current development plans.
nonamer
30-Jun-2003, 18:47
ATI does have alot more reources in terms of people to work multiple projects though, but Sony has got both ATI and Nvidia leary of the challenges of the PS 3 chip.
That's crazy IMO. NVidia has much more development resources than ATI, and they're not tied to developing a GPU for Nintendo, which I believe ATI is still committed to. Also, I think both ATI and NVidia are weary of the financial drain that developing for the XB2 would be, not the actually challenging of the PS3.
Nonamer, actually, Doom is right. ATI has a huge # of development teams spread out across North America. Remember that they have at least 2 teams for PC development alone. Look at the breathe of their product lineup, it gives you an indication of just how many teams at their disposal. They are staffing up like mad now so I think that is an indication that they plan on putting as many teams together as needed with no impact to their current development plans.
You sure of that? AFAIK, nVidia has something like 4 developement teams. Anyhow, the "breathe" of ATI's line is actually pretty thin. It's just the R300, R350, and RV350 in the past year, all minor iterations of each other. Despite NV's current woes, they've release the NV30, 31, 34, 35, as well as the nForce2 boards.
Heathen
30-Jun-2003, 19:59
ATI's done a lot more than just the R300, R350 & RV350.
Vortigern_red
30-Jun-2003, 20:00
You sure of that? AFAIK, nVidia has something like 4 developement teams. Anyhow, the "breathe" of ATI's line is actually pretty thin. It's just the R300, R350, and RV350 in the past year, all minor iterations of each other. Despite NV's current woes, they've release the NV30, 31, 34, 35, as well as the nForce2 boards.
Just to point out that ATI also have the set top box chips and the handheld chips plus P4 and athlon chipsets for both desktops and mobiles.
BTW I'm not claiming to know how big ATIs development teams are comp to Nvidias. Just pointing out that your not looking at all ATIs product lines.
Dave Baumann
30-Jun-2003, 20:18
You sure of that? AFAIK, nVidia has something like 4 developement teams.
I think both have two architectural design teams (that take on the high end parts) and the technology from these trickle down to other teams for other sectors.
Anyhow, the "breathe" of ATI's line is actually pretty thin. It's just the R300, R350, and RV350 in the past year, all minor iterations of each other. Despite NV's current woes, they've release the NV30, 31, 34, 35, as well as the nForce2 boards.
You might want to add RV250 and RV280 over the past year as well as the other market sectors already spoken of.
One analyst once said to me that ATI has more hardware engineers than NVIDIA has employee's in total - its not quite like that these days, but you shouldn't underestimate the resources they do have.
j_a_florez
01-Jul-2003, 21:02
One analyst once said to me that ATI has more hardware engineers than NVIDIA has employee's in total - its not quite like that these days, but you shouldn't underestimate the resources they do have.
More important than the quantity of resources available, though itself not an insignificant factor, is how those resources are used.
Consider this:
nVIDIA has at present 30% fewer employees yet they [have historically] produced 40% more revenue than ATi. Clearly, it's not the number of resources, but rather how they are used. However, to the casual observer, it would seem that ATi has [re]learned this lesson and nVIDIA forgotten it.
nVIDIA has at present 30% fewer employees yet they [have historically] produced 40% more revenue than ATi.
While true, ATI has [historically] been a more vertically orientated company.
This backwards compatability issue will be interesting to say the least. I question how games whose programming has forgone abstraction and been coded into nVidia native pushbuffers will work. Unless they do what SCE does and shrink the current XBox IC's onto a single 90/65nm chip, but I find this answer unlikely for a varienty of cost and inter-company IP reasons.
j_a_florez
07-Jul-2003, 18:17
nVIDIA has at present 30% fewer employees yet they [have historically] produced 40% more revenue than ATi.
While true, ATI has [historically] been a more vertically orientated company.
Exactly. Which is why it's nearly impossible to derive anything meaningful solely from the number of employees/engineers - it lacks the relational data necessary to make it a useful comparison.
This backwards compatability issue will be interesting to say the least. I question how games whose programming has forgone abstraction and been coded into nVidia native pushbuffers will work. Unless they do what SCE does and shrink the current XBox IC's onto a single 90/65nm chip, but I find this answer unlikely for a varienty of cost and inter-company IP reasons.
Agreed. I'm more inclined to believe that MS is trying to pressure nVIDIA [on pricing] by publicly dangling the carrot in front of ATi, but will go with nVIDIA in the end. However, if MS can save a buck by going to ATi, and yet retain backwards functionality, it'd be uncharacteristic of them not to. It will indeed be very interesting to see how this plays out.
Best regards,
Joe Florez
This backwards compatability issue will be interesting to say the least. I question how games whose programming has forgone abstraction and been coded into nVidia native pushbuffers will work. Unless they do what SCE does and shrink the current XBox IC's onto a single 90/65nm chip, but I find this answer unlikely for a varienty of cost and inter-company IP reasons.
Agreed. I'm more inclined to believe that MS is trying to pressure nVIDIA [on pricing] by publicly dangling the carrot in front of ATi, but will go with nVIDIA in the end. However, if MS can save a buck by going to ATi, and yet retain backwards functionality, it'd be uncharacteristic of them not to. It will indeed be very interesting to see how this plays out.
Best regards,
Joe Florez
One thing I'm wondering about: If MS really goes the ATi way - to reach an at least acceptable level of backwards compatibility, wouldn't ATi have - despite a relatively high-level SDK - to get a lot of low-level info about NV2A, far too much for nVidia's taste? Aren't there IP problems to be expected?
This backwards compatability issue will be interesting to say the least. I question how games whose programming has forgone abstraction and been coded into nVidia native pushbuffers will work. Unless they do what SCE does and shrink the current XBox IC's onto a single 90/65nm chip, but I find this answer unlikely for a varienty of cost and inter-company IP reasons.
Agreed. I'm more inclined to believe that MS is trying to pressure nVIDIA [on pricing] by publicly dangling the carrot in front of ATi, but will go with nVIDIA in the end. However, if MS can save a buck by going to ATi, and yet retain backwards functionality, it'd be uncharacteristic of them not to. It will indeed be very interesting to see how this plays out.
Best regards,
Joe Florez
One thing I'm wondering about: If MS really goes the ATi way - to reach an at least acceptable level of backwards compatibility, wouldn't ATi have - despite a relatively high-level SDK - to get a lot of low-level info about NV2A, far too much for nVidia's taste? Aren't there IP problems to be expected?
Practically, you can see the NV2A as a NV20 with a few minor additions in the Pixel Shader front, 8 zixels per clock, ... - and so on.
Furthermore, the XBox doesn't use nVidia proprietary extensions - it pretty much uses DX8, with maybe a few differences - and that SDK would then most likely work in a traditional way, using a driver.
So, eh, even slightly modifying a DX8 driver might work for the XBox. I doubt there'd be any serious issues there.
I'm more concerned about the chipset part. Heck, as someone mentionned, an nVidia chipset with an ATI GPU isn't completely out of the question, although unlikely.
Uttar
Dave Baumann
08-Jul-2003, 08:22
Its critical from a supply and and costs perspective to keep the parts to as few suppliers as possible. Also, remember that it was NVIDIA themselves that made the comment that there should be no backwards compatibility issues from the 3D side should another supplier be sought.
Futhermore, the XBox doesn't use nVidia proprietary extensions - it pretty much uses DX8, with maybe a few differences - and that SDK would then most likely work in a traditional way, using a driver
I wish you would have read my previous comment before stating this (or atleast adressed it instead of avoiding it):
Pushbuffers. Pushbuffers are the native rendering format of the Xbox GPU. When DirectX is used on the Xbox, the rendering instructions are converted into pushbuffers for execution on the GPU. A small subset of commands within the main render loop: draw primitive, z-writes, set vertexbuffer, select vertexshader, set pixelshader, etc, were reverse engineered to determine the resulting pushbuffer code. This was then used to develop an offline converter application that constructs a large pushbuffer for the whole level. Each object in the pushbuffer is preceded by a null operation (NOP), which is conditionally set as a NOP, if the following object is visible, and a jump, if the following object is not visible. The concept is similar to "execute buffers" rendering techniques in DirectX 3.0. This pushbuffer technique resulted in a reduction in the CPU set up time required for the rendering, essentially halving the frame time.
I wasn't aware that these pushbuffers would directly map a competing IHV's architecture? It's my understanding that several of the new/future generation games are forgoing the extreme abstration of a DX8 type HAL and instead going for preformance gains when possible - it is a closed box console after all.
Dave Baumann
08-Jul-2003, 08:50
Vince the first statement is "When DirectX is used the rendering instructions are converted..." indicating that the game code itself will be DirectX, how that executes at a hardware level is beside the point since its up to the compiler to take the directX code and convert that into machine operation.
What you need to understand to evaluate whether that is an issue is whether any developers have used the "pushbuffers" directly or they just use DX code.
What you need to understand to evaluate whether that is an issue is whether any developers have used the "pushbuffers" directly or they just use DX code.
Dave, I wouldn't have posted it if it wasn't the case. Besides, the quote is from State of Emergency (SoE) a game that you, yourself, can buy today for XBox. That excerpt was a quote from two developers during GDC2003 on their experience in porting their hand-tuned VU microcode from PS2 to the XBox.
What do you think, I'm posting hypotheticals just to argue? heh.
PS. After rereading your responce, I'd suggest you reread the quote from above as I think you're missing what they did. Here's another and the link below:
Since the performance of the game was a result of this exploitation of the PS2 architecture, the initial conversion to Xbox, resulted in lower overall performance than the PS2. Even though, based on raw processing power, the Xbox might have been expected to perform at least the same, if not better, than the PS2. This necessitated a change to the Xbox renderer, specifically converting the code from using DirectX drawing primitives, to pushbuffers, the native rendering format of the Xbox GPU. The result is that SOE on the Xbox runs at 60fps in the single player mode, twice the frame-rate of the original PS2 version. http://www.gamasutra.com/gdc2003/features/20030307/dobson_02.htm
Dave Baumann
08-Jul-2003, 09:00
This technique doesn't necessarily mean that it's NVIDIA specific rendering, but rather a characteristic of how instruction are packaged and sent to the GPU, I don't see any reason to assume that this would not work on other hardware - again, NVIDIA don't think this is an issue to MS.
antlers
08-Jul-2003, 23:27
I guess this means that if there were technical info NVidia didn't want ATI to have, they couldn't reveal it to Microsoft, which in turn couldn't reveal it to XBox developers.
Heathen
09-Jul-2003, 06:45
I suspect that if MS had any sense they would have put a free rights clause into the develoment contract.
Can anyone else see an xbox 2 using a a64 , power vr 3d chip and a video lodgic sound chip (they still make sound chips right?)
There seems to be a lot of confusion about the Xbox GPU... Hopefully this may clarify things (and not break any NDAs...)
Xbox Direct3D is different from PC Direct3D, the PC interfaces are mostly there but lots of games don't use them. There are LOTS of things that are in hardware specific format AND use 'features' that are not commonly availible. Except for ports, lots of developers are working at a much closer level than on PC. Notable things includes working with the register combiners directly, relying on pixel/texture formats (i.e. accessing depth/stencil buffer data as colour by just pretending the depth/stencil buffer is a ARGB8 texture) and non-standard alpha test functionality (so-called AlphaKill).
The push buffers are rendering commands in a DMA list. There are the interface between software and GPU. There is no Direct3D DLL on Xbox. The Direct3D libraries are statically linked in the program and output push-buffers (i.e. no different from a developer writing there own push-buffer outputting routines (from a compat point of view) ). MS allow Devs to work on the push-buffers themselves rather than using Direct3D. There is even a library for the PC that will output the push-buffers, which allows a off-line PC convertor to generate the native Xbox GPU commands directly, by just calling Direct3D like routines on the PC.
The important things to note about any GPU compatiblity.
A) Must include pixel/Texture formats, bugs and features (i.e. you must be able to do AlphaKill, even though D3D or OpenGL have no concept of it)
B) Must be able to digest push-buffers, as there is no DLL to intercept. I.e. no magic driver swap, requires hardware emulation
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